Look, Drew, our point of contention is this. You're arguing that the Profession's use of the phrase "of the mind and will" necessarily has it talking about giving the unconditional assent of faith to the non-definitive acts of the Magisterium, forcing everyone to believe the non-infallible acts of the Magisterium with the certainty of faith.
You based this on nothing other than the phrase "of the mind and will". I point out that Monsigonor Fenton referred to the conditional religious submission as being "internal" and "of the mind" ... to distinguish it from the merely external submission.
That passage from the Profession specifically refers to RELIGIOUS submission, which is a well-known term among theologians, who routinely qualify it as "internal" and "of the mind" vs. merely external. Your quote from Vatican I refers to submission "by faith" and is describing supernatural faith as involving both the intellect and the will, the will because the truths of revelation are unknowable by the intellect on its own and therefore requires a submission of the will. You're trying to compare apples and oranges.
There's absolutely NO WAY in which the Conciliarists now believe that non-definitive acts of the Magisterium must be accepted as de fide. In fact, most Conciliarist theologians circuмscribe the scope of infallibility and of what's de fide to the extreme.
As for those who accuse people who don't accept the need for religious submission as being heretics, they're mistaken regarding the theological note. It's only theologically certain and therefore not strictly heresy.